We propose to isolate a series of cosmid clones containing human MHC linked complement and immune response related genes. Novel methods for "saltation" cloning will then be evolved and applied to generate a series of DNA probes spanning the region between these cosmid clones and potentially providing a fairly uniform representation of DNA probes extending to the SB locus to the HLA-B locus in man. DNA in this region will be examined for otherwise unrecognized genes and for polymorphisms that may be used in association and linkage analysis of propensity to insulin dependent diabetes mellitus.